BL0930

BL0930
FEATURES
Single Phase Energy Meter IC
with Integrated Oscillator
DESCRIPTION
High accuracy, less than 0.1% error over a
The BL0930 is a low cost, high accuracy, high
dynamic range of 500 : 1
stability, simple peripheral circuit electrical energy
Exactly measure the real power in the positive
meter IC. The meter based on the BL0930 is intended
orientation and negative orientation, calculate the
for using in single-phase, two-wire distribution
energy in the same orientation
systems.
A PGA in the current channel allows using small
The BL0930 adopts the oversample technology
value shunt and burden resistance
and digital signal processing technology. It can
The low frequency outputs F1 and F2 can
exactly measure the real power in the positive
directly drive electromechanical counters and two
orientation and negative orientation and calculate the
phase stepper motors and the high frequency output
energy in the same orientation. Moreover, BL0930
CF, supplies instantaneous real power, is intended for
supplies the negative orientation indication on Pin12
calibration and communications
(REVP). Therefore, the meter using the BL0930 has
great capability to avoid fault condition.
The logic outputs REVP can be used to indicate a
potential orientation
The BL0930 supplies average real power
Low static power (typical value of 15mW).
information on the low frequency outputs F1 (Pin16)
The technology of SLiM (Smart–Low–current–
and F2 (Pin15). These logic outputs may be used to
Management )
is used.
directly drive an electromechanical counter and
On-Chip power supply detector
two-phase stepper motors. The CF (Pin14) logic
On-Chip anti-creep protection
output gives instantaneous real power information.
On-Chip oscillator
This output is intended to be used for calibration
On-Chip voltage reference of 2.5V±8% (typical
purposes or interface to an MCU.
temperature coefficient of 30ppm/℃)，with external
The BL0930 adopts the technology of SLim and
overdrive capability
decreases greatly the static power. This technology
also decreases the request for power supply.
Single 5V supply
BL0930 thinks over the stability of reading
error in the process of calibration.. An internal no-load
threshold ensures that the BL0930 does not exhibit
Interrelated patents are pending
any creep when there is no load.
BLOCK DIAGRAM
VREF
VDD
1
16
F1
V2P
2
15
F2
V2N
3
14
CF
V1N
4
13
NC
V1P
5
12
REVP
GND
6
11
G
VREF
7
10
S0
SCF
8
9
S1
BL0930
VDD
voltage
reference
V1P
V1N
current
sampling
internal
oscillator
high
pass
filter
analog to
digital
BL0930
digital
multiplication
V2P
V2N
voltage
sampling
high
pass
filter
analog to
digital
logical
SCF
S1
power
detector
low
pass
filter
digital to
frequency
and output
REVP
CF
F1
F2
control
S0
G
DIP 16
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3/28/2007
Single Phase Energy Meter IC
with Integrated Oscillator
BL0930
PIN DESCRIPTIONS
Pin
Symbol
DESCRIPTIONS
1
VDD
Provides the supply voltage for the circuitry. It should be maintained at 5 V±5% for
specified operation.
2,3
V2P,V2N
Negative and Positive Inputs for Voltage Channel. These inputs provide a fully
differential input pair. The maximum differential input voltage is ±165 mV for
specified operation.
4,5
V1N ,V1P
Inputs for Current Channel. These inputs are fully differential voltage inputs with a
maximum signal level of ±660 mV
6
GND
Provides the ground reference for the circuitry.
7
VREF
On-Chip Voltage Reference. The on-chip reference has a nominal value of 2.5V ±
8% and a typical temperature coefficient of 30ppm/℃. An external reference source
may also be connected at this pin.
8
SCF
Calibration Frequency Select. This logic input is used to select the frequency on the
calibration output CF.
9,10
S1,S0
Output Frequency Select. These logic inputs are used to select one of four possible
frequencies for the digital-to-frequency conversion. This offers the designer greater
flexibility when designing the energy meter.
11
G
Gain Select. These logic inputs are used to select one of four possible gains for
current channel. The possible gains are 1 and 16.
Negative Indication. Logic high indicates negative power, i.e., when the phase angle
12
REVP
13
NC
Reserved.
14
CF
Calibration Frequency. The CF logic output gives instantaneous real power
information. This output is intended to use for calibration purposes.
15,16
F2,F1
Low-Frequency. F1 and F2 supply average real power information. The logic outputs
can be used to directly drive electromechanical counters and 2-phase stepper motors.
between the voltage and current signals is greater that 90°. This output is not latched
and will be reset when positive power is once again detected.
ABSOLUTE MAXIMUM RATINGS
( T = 25 ℃ )
Parameter
Symbol
Value
Unit
Analog &Digital power Voltage VDD
VDD
-0.3~+7(max)
V
Analog Input Voltage of Channel 2 to GND
V (V)
VSS+0.5≤V(v)≤VDD-0.5
V
Analog Input Voltage of Channel 1 to GND
V (I)
VSS+0.5≤V(i)≤VDD-0.5
V
Operating Temperature Range
Topr
-40~+85
℃
Storage Temperature Range
Tstr
-55~+150
℃
400
mW
Power Dissipation（DIP16）
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BL0930
Single Phase Energy Meter IC
with Integrated Oscillator
Electronic Characteristic Parameter
(T=25℃, VDD=5V, On-Chip Oscillator )
Parameter
Symb
ol
1 Power Current
IVDD
Input High Voltage
VIH
Input Low Voltage
VIL
Input Capacitance
CIN
Test Condition
Measure
Pin
Min
Value
Pin1
VDD=5V
VDD=5V
3 Logic Output Pins
F1, F2
Max
Value
3.5
Unit
mA
2
V
1
V
10
pF
Pin16, 15
Output High Voltage
VOH1
IH=10mA
Output Low Voltage
VOL1
IL=10mA
Output Current
4.4
V
0.5
IO1
10
4 Logic Output Pins
CF, REVP,
V
mA
Pin14, 12
Output High Voltage
VOH2
IH=10mA
Output Low Voltage
VOL2
IL=10mA
5 On-chip Reference
Vref
VDD=5V
6 Analog Input Pins
V1P, V1N
V2N, V2P
Maximum Input Voltage
Typical
Value
4
Pin7
2.3
V
2.5
0.5
V
2.7
V
±1
V
Pin 5,4,
3,2
VAIN
DC Input Impedance
330
Input Capacitance
Kohm
10
pF
7 Accuracy
Measurement Error on
Channel 1 and 2
Phase Error
Channels
between
Channel 1 Lead 37°
(PF=0.8Capacitive)
Pin14
0.1
0.3
%
Channel 1 Lags
(PF=0.5Inductive)
Pin14
0.1
0.3
%
8 Start Current
ISTART
Ib=5A C=3200,
Pin4
0.2%Ib
A
cosϕ=1
Voltage Channel
Inputs ±110mV
Gain of Current
Channel 16
9 Positive and Negative
Real Power Error (%)
ENP
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Vv=±110mV,V(I)
=2mV, cosϕ=1
Vv=±110mV,V(I)
-3Total 3 Pages
Pin14
0.4
3/28/2007
%
BL0930
10 Power Supply
Monitor Voltage
Vdown
=2mV, cosϕ=-1
Power Supply
vary from 3.5V to
5V,and Current
Channel with
Full-Scale Signal
Pin14
Single Phase Energy Meter IC
with Integrated Oscillator
3.9
4
4.1
TERMINOLOGY
1) Measurement Error
The error associated with the energy measurement made by the BL0930 is defined by the
following formula:
Pencentage Error =
Energy Re gistered by the BL0930 − True Energy
× 100%
True Energy
2) Nonlinear Error
The Nonlinear Error is defined by the following formula:
eNL%＝[(Error at X-Error at Ib) / (1+Error at Ib )]*100%
When V(v)= ±110mV, cosϕ=1, over the arrange of 5%Ib to 800%Ib, the nonlinear error should be
less than 0.1%.
3) Positive And Negative Real Power Error
When the positive real power and the negative real power is equal, and V(v) =±110mV, the test
current is Ib, then the positive and negative real power error can be achieved by the following
formula:
eNP%=|[(eN%-eP%)/(1+eP%)]*100%|
Where: eP% is the Positive Real Power Error, eN% is the Negative Real Power Error.
5) Power Supply Monitor
BL0930 has the on-chip Power Supply monitoring The BL0930 will remain in a reset
condition until the supply voltage on VDD reaches 4 V. If the supply falls below 4 V, the BL0930
will also be reset and no pulses will be issued on F1, F2 and CF.
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V
BL0930
Single Phase Energy Meter IC
with Integrated Oscillator
TIMING CHARACTERISTIC
(VDD =5V, GND =0V, On-Chip Reference, On-Chip Oscillator , Temperature range: -40~+85°C)
Parameter
t1
Value
144ms
t2
Comments
F1 and F2 pulse-width (Logic Low). When the power is low, the
t1 is equal to 144ms; when the power is high, and the output
period exceeds 550ms, t1 equals to half of the output period.
F1 or F2 output pulse period.
t3
½ t2
Time between F1 falling edge and F2 falling edge.
t4
71ms
CF pulse-width (Logic high). When the power is low, the t4 is
equal to 71ms; when the power is high, and the output period
exceeds 180ms, t4 equals to half of the output period.
t5
t6
CF Pulse Period. See Transfer Function section.
CLK/4
Minimum Time Between F1 and F2.
Notes:
1) CF is not synchronous to F1 or F2 frequency outputs.
2) Sample tested during initial release and after any redesign or process change that may affect this
parameter.
THEORY OF OPERATION
Principle of Energy Measure
In energy measure, the power information varying with time is calculated by a direct
multiplication of the voltage signal and the current signal. Assume that the current signal and the
voltage signal are cosine functions; Umax, Imax are the peak values of the voltage signal and the
current signal; ωis the angle frequency of the input signals; the phase difference between the
current signal and the voltage signal is expressed asφ. Then the power is given as follows:
p (t ) = U max cos( wt ) × I max cos( wt + ϕ )
If φ=0:
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BL0930
p (t ) =
Single Phase Energy Meter IC
with Integrated Oscillator
U max I max
[1 + cos(2 wt )]
2
If φ≠0:
p (t ) = U max cos(ωt ) × I max cos(ωt + Φ )
= U max cos(ωt ) × [I max cos(ωt ) cos(Φ ) + I max sin(ωt ) sin(Φ )]
U max I max
[1 + cos(2ωt )] cos(Φ ) + U max I max cos(ωt ) sin(ωt ) sin(Φ )
2
U I
U I
= max max [1 + cos(2ωt )] cos(Φ ) + max max sin( 2ωt ) sin(Φ)
2
2
U I
U I
= max max cos(Φ) + max max [cos(2ωt ) cos(Φ ) + sin(2ωt ) sin(Φ)]
2
2
U max I max
U max I max
=
cos(Φ) +
cos(2ωt + Φ)
2
2
=
P(t) is called as the instantaneous power signal. The ideal p(t) consists of the dc component and ac
component whose frequency is 2ω. The dc component is called as the average active power, that
is:
P=
U max I max
cos(ϕ )
2
The average active power is related to the cosine value of the phase difference between the voltage
signal and the current signal. This cosine value is called as Power Factor (PF) of the two channel
signals.
Figure1.
The Effect of phase
When the signal phase difference between the voltage and current channels is more than 90°, the
average active power is negative. It indicates the user is using the electrical energy reversely.
Operation Process
In BL0930, the two ADCs digitize the voltage signals from the current and voltage transducers.
These ADCs are 16-bit second order sigma-delta with an oversampling rate of 900 kHz. This
analog input structure greatly simplifies transducer interfacing by providing a wide dynamic range
for direct connection to the transducer and also simplifying the antialiasing filter design. A
programmable gain stage in the current channel further facilitates easy transducer interfacing. A
high pass filter in the current channel removes any dc component from the current signal. This
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3/28/2007
BL0930
Single Phase Energy Meter IC
with Integrated Oscillator
eliminates any inaccuracies in the real power calculation due to offsets in the voltage or current
signals.
The real power calculation is derived from the instantaneous power signal. The instantaneous
power signal is generated by a direct multiplication of the current and voltage signals. In order to
extract the real power component (i.e., the dc component), the instantaneous power signal is
low-pass filtered. Figure 2 illustrates the instantaneous real power signal and shows how the real
power information can be extracted by low-pass filtering the instantaneous power signal. This
scheme correctly calculates real power for nonsinusoidal current and voltage waveforms at all
power factors. All signal processing is carried out in the digital domain for superior stability over
temperature and time.
I
V
current
sampling
voltage
sampling
analog to
digital
high pass
filter
analog to
digital
digital
multiplication
high pass
filter
low pass
filter
CF
F1
digital to
frequency
F2
instantaneous real
power signal
instantaneous
power signal p(t)
V*I
integral
p(t)=i(t)*v(t)
v(t)=V*cos(wt)
i(t)=I*cos(wt)
V*I
2
p(t)=
V*I
2
V*I
2
[1+cos(2wt)]
t
t
Figure 2.
Signal Processing Block Diagram
The low frequency output of the BL0930 is generated by accumulatingm this real power
information. This low frequency inherently means a long accumulation time between output
pulses. The output frequency is therefore proportional to the average real power. This average real
power information can, in turn, be accumulated (e.g., by a counter) to generate real energy
information. Because of its high output frequency and hence shorter integration time, the CF
output is proportional to the instantaneous real power. This is useful for system calibration
purposes that would take place under steady load conditions.
VOLTAGE CHANNEL INPUT
The output of the line voltage transducer is connected to the BL0930 at this analog input. As
Figure4 shows that channel V2 is a fully differential voltage input. The maximum peak differential
signal on Channel 2 is ±165mV. Figure4 illustrates the maximum signal levels that can be
connected to the BL0930 Voltage Channel.
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3/28/2007
BL0930
Single Phase Energy Meter IC
with Integrated Oscillator
V1
+165mV
Maximun input differential voltage
±165mV
V2P
+
V1
-
V2N
V2
V2
Maximun input commonmode
voltage 100mV
-165mV
AGND
Figure 4.
Voltage Channels
Voltage Channel must be driven from a common-mode voltage, i.e., the differential voltage signal
on the input must be referenced to a common mode (usually GND). The analog inputs of the
BL0930 can be driven with common-mode voltages of up to 100 mV with respect to GND.
However, best results are achieved using a common mode equal to GND.
Figure5 shows two typical connections for Channel V2. The first option uses a PT (potential
transformer) to provide complete isolation from the mains voltage. In the second option, the
BL0930 is biased around the neutral wire and a resistor divider is used to provide a voltage signal
that is proportional to the line voltage. Adjusting the ratio of Ra and Rb is also a convenient way
of carrying out a gain calibration on the meter.
RF
CT
V2P
CF
±165mV
RF
AGND
V2N
+
-
CF
AGND
Phase Neutral
AGND
CF
Ra
Rb
AGND
Rv
AGND
±165mV
V2P
Phase Neutral
RF
AGND
V2N
Ra >> RF
Rb+Rv=RF
Figure 5.
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+
-
CF
AGND
AGND
Typical Connections for Voltage Channels
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BL0930
Single Phase Energy Meter IC
with Integrated Oscillator
CURRENT CHANNEL INPUT
The voltage outputs from the current transducers are connected to the BL0930 here. The
maximum differential voltage on Current Channel 2 is ±660mV. The maximum common-mode
voltage is ±100mV.
Power Supply Monitor
The BL0930 contains an on-chip power supply monitor. If the supply is less than 4V±5% then
the BL0930 will go in an inactive state, i.e. no energy will be accumulated when the supply
voltage is below 4V. This is useful to ensure correct device operation at power up and during
power down. The power supply monitor has built-in hysteresis and filtering. This gives a high
degree of immunity to false triggering due to noisy supplies.
The trigger level is nominally set at 4V, and the tolerance on this trigger level is about ±5%. The
power supply and decoupling for the part should be such that the ripple at VDD does not exceed
5V±5% as specified for normal operation.
SLiM technology
The BL0930 adopts the technology of SLiM (Smart Low current Management) to decrease the
static power greatly. The static power of BL0930 is about 12mW. It is half of the previous product
BL0955 (about 25mW ).This technology also decreases the request for power supply design.
BL09XX series products used 0.35um CMOS process. The reliability and consistency are
advanced.
OPERATION MODE
Transfer Function
The BL0930 calculates the product of two voltage signals (on Channel 1 and Channel 2) and then
low-pass filters this product to extract real power information. This real power information is then
converted to a frequency. The frequency information is output on F1 and F2 in the form of active
low pulses. The pulse rate at these outputs is relatively low. It means that the frequency at these
outputs is generated from real power information accumulated over a relatively long period of
time. The result is an output frequency that is proportional to the average real power. The average
of the real power signal is implicit to the digital-to-frequency conversion. The output frequency or
pulse rate is related to the input voltage signals by the following equation.
Freq =
22.4 × V (v) × V (i ) × FZ × G
2
VREF
Freq——Output frequency on F1 and F2 (Hz)
V(v)——Differential rms voltage signal on Channel 1 (volts)
V(i)——Differential rms voltage signal on Channel 2 (volts)
G——1or 16, depending on the PGA gain selection, using logic inputs G
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Single Phase Energy Meter IC
with Integrated Oscillator
BL0930
Vref——The reference voltage (2.5V±8%) (volts)
Fz——One of four possible frequencies selected by using the logic inputs S0 and S1.
S1
S0
Fz(Hz)
XTAL/CLKIN
0
0
1.7
CLKIN/2^21
0
1
3.4
CLKIN/2^20
1
0
6.8
CLKIN/2^19
1
1
13.6
CLKIN/2^18
Gain Selection
By select the digital input G voltage (5V or 0V), we can adjust the gain of current channel.
We can see that while increasing the gain, the input dynamic range is decreasing.(Default G is
zero)
G
Gain
Maximum Differential
Signal
1
1
±660mV
0
16
±41mV
Frequency Output CF
The pulse output CF (Calibration Frequency) is intended for use during calibration. The output
pulse rate on CF can be up to 128 times the pulse rate on F1 and F2. The following Table shows
how the two frequencies are related, depending on the states of the logic inputs S0, S1 and SCF.
Mode
SCF
S1
S0
CF/F1 (or F2)
1
1
0
0
128
2
0
0
0
64
3
1
0
1
64
4
0
0
1
32
5
1
1
0
32
6
0
1
0
16
7
1
1
1
16
8
0
1
1
2048
Because of its relatively high pulse rate, the frequency at this logic output is proportional to the
instantaneous real power. As is the case with F1 and F2, the frequency is derived from the output
of the low-pass filter after multiplication. However, because the output frequency is high, this real
power information is accumulated over a much shorter time. Hence less averaging is carried out in
the digital-to-frequency conversion. With much less averaging of the real power signal, the CF
output is much more responsive to power fluctuations.
ANALOG INPUT RANGE
The maximum peak differential signal on Voltage Channel is ± 165 mV, and the common-mode
voltage is up to 100 mV with respect to GND.
The analog inputs V1P and V1N have the same maximum signal level restrictions as V2P and
V2N. The maximum differential voltage is ±660 mV and the maximum common-mode signal is
±100 mV.
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Total 10 Pages
Single Phase Energy Meter IC
with Integrated Oscillator
BL0930
The corresponding Max Frequency of CF/F1/F2 is shown in the following table.
SCF
S1
S0
Fz
Max Frequency
of F1, F2 (Hz)
DC
CF Max Frequency (Hz)
AC
DC
AC
1
0
0
1.7
0.72
0.36
128×F1,F2=92.16
128×F1,F2=46.08
0
0
0
1.7
0.72
0.36
64×F1,F2=46.08
64×F1,F2=23.04
1
0
1
3.4
1.44
0.72
64×F1,F2=92.16
64×F1,F2=46.08
0
0
1
3.4
1.44
0.72
32×F1,F2=46.08
32×F1,F2=23.04
1
1
0
6.8
2.88
1.44
32×F1,F2=92.16
32×F1,F2=46.08
0
1
0
6.8
2.88
1.44
16×F1,F2=46.08
16×F1,F2=23.04
1
1
1
13.6
5.76
2.88
16×F1,F2=92.16
16×F1,F2=46.08
0
1
1
13.6
5.76
2.88
2048×F1,F2=11.8K
2048×F1,F2=5.9K
Package Dimensions
1、DIP16
2、SOP16
Notice： Sample tested during initial release and after any redesign or process change
that may affect parameter. Specification subject to change without notice. Please ask
for the newest product specification at any moment.
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